A science experiment for kids

The 'submarine' dives when you squeeze the bottle and floats when you relieve the grip.








With suitable amount of Blu-Tack, the 'submarine' can float in water.









The photo shows how the paper clip is bent and inserted into the straw.








Materials required for the experiment (a paper clip, a straw, some Blu-Tack and a plastic bottle)






My family paid a visit to the public library last month. My wife was looking for story books for Ching’s reading scheme. I liked to try something new and I chose a book about science experiments. Most of the materials required for experiments mentioned in the book are easily available. I tried one with my daughter and she enjoyed it very much. She got a lot of fun when doing this experiment. Here I would like to share with you the key steps of this experiment.

‘Submarine – sink or float’

Materials:
(1) a plastic bottle
(2) some Blu Tack
(3) a paper clip
(4) a straw (about 6cm long)

Procedure:

(1) Bend the paper clip as shown in the photo.
(2) Insert both ends of the paper clip into the straw.
(3) Attach some Blu Tack to the paper clip
(4) Adjust the amount of Blu Tack so that the ‘submarine’ can freely float in water.
(5) Put the ‘submarine’ in a plastic bottle fully filled with water. Remember to screw the bottle cap tightly.
(6) If you want to sink the submarine, just squeeze the bottle hard.
(7) By controlling the amount of water you squeeze into the straw, you can adjust the position of the ‘submarine’ as you wish.